Heater Vents Issue Left/Right different temps

[kent55]

Here is an odd 1. The 2 center air vents just above the car radio on my 07 Legacy are blowing different temperature air when I select the upper vents. The driver side is what I expect "conditioned air" (Hot or cold AC) to be. The passenger side is not as extreme, even the far right vent by the passenger door is not hot or conditioned. I removed the 2 center vents (clock cluster) and the issue seems to be much further back in the dashboard.

Any idea? The dash was out with Air bag recall. This may have been when this started.

Edited January 18, 2023 by kent55

[KZJonny]

Hvac actuators. Passenger side is easy to swap, so you got lucky there.

Driver’s side difficult to impossible depending on how big your hands are.

lots of threads on this topic.

jaylew’s is the one I read most recently.

[kent55]

Oh, I always though the actuators only did feet, face and Defrost change. Did not realize they also affected left and right if broken.

I will search that. Thanks for the heads up.

Edited January 18, 2023 by kent55

[KZJonny]

I think in this case, it’s the blend actuator that mixed hot and cold air…

The part numbers and locations are in that thread, I think. Including supercession numbers and which currently available ones work…

[Pleides]

The one that makes your passenger side blow the wrong temp is probably the easiest one to change. Grab a new cabin filter from the Subaru dealer when you pick up your new actuator and it's a double whammy.

[kent55]

Thanks to both of you.

[Pleides]

On 1/23/2023 at 8:14 PM, kent55 said:

Thanks to both of you.

No worries. I'd recommend a 90-degree angle screwdriver for removing the actuator and also would recommend taking your blower motor out and cleaning it while you're in there. 

[kent55]

Cool ideas

[SubOperator]

FWIW, I ended up replacing the heater core (small radiator) in our Tribeca after having issue with passenger side blowing much colder air for few years. Blamed the actuators but the problem ended up being the heater core.

[KZJonny]

1 hour ago, SubOperator said:

FWIW, I ended up replacing the heater core (small radiator) in our Tribeca after having issue with passenger side blowing much colder air for few years. Blamed the actuators but the problem ended up being the heater core.

Also a possibility.

I backflushed mine with as much pressure as I dared without breaking it…

Got 2x as hot air on the drivers side… passenger was still cold as a nuns tit.

I’d say do both, but this time of year, a heater core flush won’t be much fun. At least doing the actuator you stay dry.

[SubOperator]

1 hour ago, KZJonny said:

Also a possibility.

I backflushed mine with as much pressure as I dared without breaking it…

Got 2x as hot air on the drivers side… passenger was still cold as a nuns tit.

I’d say do both, but this time of year, a heater core flush won’t be much fun. At least doing the actuator you stay dry.

Flushing wouldn't work - they way the heater core is mounted on Tribeca the deposits accumulate in a way that flushing just does not get them out. One guy on Tribeca forums did a cut up of heater core he took out of his Tribeca - the deposits were sitting in the part of the heater core that was hard to reach. So replacement was an easier, and more guaranteed option.

That's all for Tribeca of course, idk if the heater core is mounted the same way on BL/BP. But the replacement was not too bad, I just undid the clips that held the metal piping going in the heater core itself - there are rubber seals that work just fine when you pop them back in the new heater core. Undo the lines, slide the old one out, slide the new one in, put the lines back in and you're done. There is some spill but I managed to do it without draining the coolant from the system. Old garage towel dealt with whatever ran out of the heater core hoses.

OEM  Subaru heater core was ~90 bucks. There is a Toyota part that is exact match.

[LGTmakes3]

PM'd you

[KZJonny]

On 1/25/2023 at 7:54 PM, SubOperator said:

Flushing wouldn't work - they way the heater core is mounted on Tribeca the deposits accumulate in a way that flushing just does not get them out. One guy on Tribeca forums did a cut up of heater core he took out of his Tribeca - the deposits were sitting in the part of the heater core that was hard to reach. So replacement was an easier, and more guaranteed option.

That's all for Tribeca of course, idk if the heater core is mounted the same way on BL/BP. But the replacement was not too bad, I just undid the clips that held the metal piping going in the heater core itself - there are rubber seals that work just fine when you pop them back in the new heater core. Undo the lines, slide the old one out, slide the new one in, put the lines back in and you're done. There is some spill but I managed to do it without draining the coolant from the system. Old garage towel dealt with whatever ran out of the heater core hoses.

OEM  Subaru heater core was ~90 bucks. There is a Toyota part that is exact match.

Interesting. I'll have to take a look at some parts diagrams and see if that parts look at all similar. Aside from Subaru building everything from the same parts bin, I don't know why the heater core would similar between the BP/BL and Tribeca, but they could be the same damn thing, for all I know.

If time permits, another option to explore could be to remove and loop the hoses going to the core. Drain/blow the core out and fill with 10% acetic acid. (Cleaning strength vinegar.) If the deposits aren't ridiculous a few days of that could help and that shouldn't be enough exposure to acid to damage the core. if It did leak because of that, I would think it was on the way out anyhow.

[xt2005bonbon]

Yeah, my bet is also on the heater core. Usually, you know you actuators are acting up when you hear that annoying clicking around the center of the dash. My passenger side has never blown as hot as the driver side and vice-versa with cold AC. I also tried to do a reverse flush and still no luck. Also changed a few actuators as they were clicking. I just need to set some time aside to install a new heater core. Keep forgetting about it..